Naval Surface Warfare Center

About: Naval Surface Warfare Center is a facility organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Radar & Sonar. The organization has 2855 authors who have published 3697 publications receiving 83518 citations. The organization is also known as: NSWC.

Structure, morphology and magnetic properties of Mg((x))Zn((1 - x))Fe2O4 ferrites prepared by polyol and aqueous co-precipitation methods: a low-toxicity alternative to Ni((x))Zn((1 - x))Fe2O4 ferrites.

Abstract: The synthesis and properties of Mg((x))Zn((1 - x))Fe(2)O(4) spinel ferrites as a low-toxicity alternative to the technologically significant Ni((x))Zn((1 - x))Fe(2)O(4) ferrites are reported. Ferrite nanoparticles have been formed through both the polyol and aqueous co-precipitation methods that can be readily adapted to industrial scale synthesis to satisfy the demand of a variety of commercial applications. The structure, morphology and magnetic properties of Mg((x))Zn((1 - x))Fe(2)O(4) were studied as a function of composition and particle size. Scanning electron microscopy images show particles synthesised by the aqueous co-precipitation method possess a broad size distribution (i.e. ∼ 80-120 nm) with an average diameter of the order of 100 nm ± 20 nm and could be produced in high process yields of up to 25 g l(-1). In contrast, particles synthesised by the polyol-based co-precipitation method possess a narrower size distribution with an average diameter in the 30 nm ± 5 nm range but are limited to smaller yields of ∼ 6 g l(-1). Furthermore, the polyol synthesis method was shown to control average particle size by varying the length of the glycol surfactant chain. Particles prepared by both methods are compared with respect to their phase purity, crystal structure, morphology, magnetic properties and microwave properties.

Development of a Seebeck coefficient Standard Reference Material

Abstract: We have successfully developed a Seebeck coefficient Standard Reference Material (SRM ™ ), Bi 2 Te 3 , that is crucial for inter-laboratory data comparison and for instrument calibration. Certification measurements were performed using two different techniques on 10 samples randomly selected from a batch of 390 bars. The certified Seebeck coefficient values are provided from 10 to 390 K. The availability of this SRM will validate the measurement accuracy, leading to a better understanding of the structure/property relationships, and the underlying physics of new and improved thermoelectric materials. An overview of the measurement techniques and data analysis is given.

Early decomposition chemistry of NTO, (3-Nitro-1,2,4-Triazol-5-One)

Abstract: The early reaction chemistry of NTO, (3-Nitro-1,2,4-triazol-5-one) induced by, drop weight impact, shock, heat and radiation has been investigated. X-ray photoelectron spectroscopy XPS and chemical ionization mass spectrometry CIMS were employed to observe and identify the partial decomposition products in the damaged samples. Several reaction intermediates have been identified, the focus of the reaction being the single nitro group present on this molecule. XPS spectra indicated in all cases the loss of NO2 concentration in response to damage. Additional chemical states were suggested in the XPS N(ls) spectrum by the appearance of a new peak at a binding energy below that of the triazol ring nitrogens. Mass spectrometry provided the molecularly specific information needed to identify molecular species resulting from the decomposition reactions. Relative to the parent NTO molecule, mass peaks were observed that corresponded to the loss of one O atom, an NO fragment, and a HONO.

Production of sulfide minerals by sulfate-reducing bacteria during microbiologically influenced corrosion of copper

Abstract: Mineralogical data, thermodynamic stability (Pourbaix) diagrams, and the simplexity principle for precipitation reactions were used to evaluate corrosion product mineralogy on copper alloy...